Let θ∈(0,π4) and t1=(tanθ)tanθ, t2=(tanθ)cotθ, t3=(cotθ)tanθ then t4=(cotθ)cotθ, then
Let θ∈(0,π4) and t1=(tanθ)tanθ,t2(tanθ)cott3=(cotθ)tanθ and t4(cotθ)tanθ , then